Voltammetric determination of copper(II) ion using cyanex 921 modified pencil graphite electrodes. Indian Journal of Chemical Technology (IJCT), [S. l.], v. 33, n. 2, p. 196–206, 2026. DOI: 10.56042/ijct.v33i2.22855. Disponível em: https://or.niscpr.res.in/index.php/IJCT/article/view/22855. Acesso em: 30 may. 2026.